I haven't had the issue of falling asleep during a large battle... When I took on the entire goblin camp, yes, it did take a while for 18 enemies to move and attack and it was a little dull just waiting for my turn, I'll grant you that, but...

I don't think this is entirely Larian's fault. This is just D&D.

As a DM, I had a tabletop game where I pitted my players (3 players + 1 NPC all at level 6) against a horde of goblins. They had out-levelled (the basic 1/4 CR) goblins, but I wanted them to fight goblins for story reasons, so I just threw a ton of them at the players. And yeah... they almost fell asleep as I moved mins and rolled my d20 for 30 goblins. They did not find it fun at all and I'm never going to do that to them again. Lesson learned.

As for real-time... I don't see how it would work and stay with the 5e rules. You have movement limits, you have actions, bonus actions and reactions. I played BG1+2, Icewind Dale, more recently: Pathfinder - Kingmaker etc. and I was never, ever a fan of the real-time with pause. It may appeal to some players because it's faster-paced, but it isn't D&D (as far as I'm concerned). The number of times I've laid down a fireball in RTwP games only to have it explode with nobody in the blast area because they'd all moved out of it and were now killing the wizard in melee... it's a bad fit with D&D rules. I think if you had RTwP in BG3, you'd just get overwhelmed and die constantly.

A better suggestion would be to have a game option slider to accelerate enemy moves/animations in combat. Find combat too slow? Change the slider from 100% to 200% and just watch them fly around the map until your turn. And, it may seem flippant, but the other option is just to try and avoid large battles with more than 4 or 5 enemies. Not always possible, sure, but one way to deal with it. (And if you do need to have a large battle, use AoE stuff - grenades like Alchemist's Fire + Grease spell so that you whittle down the numbers quickly.)